The present invention relates to protective lenses, particularly to eyewear with polarized lens, and is more especially directed to eyewear with polarized lens for water sports, such as swimming goggles, diving masks and the like.
Polarization is one of the fundamental properties of light waves. Generally, in an unpolarized wave, the vibration in a plane perpendicular to the ray appears to be oriented in all directions with equal probability. In a polarized wave the displacement direction of the vibrations is completely predictable. When light is reflected from a surface, it is partially polarized. When it is reflected at a particular angle, for example 53xc2x0 in the case of water, it is completely polarized. Such polarized light produces undesirable effects which are an increase in brightness and a reduction in colour saturation such that glare occurs. This makes objects viewed in the presence of glare appear to be washed-out and causes eye strain and discomfort. Tinted glasses or plastic lenses cannot solve the problem of glare. Such glare is particularly acute when reflected from water surfaces, the surface of snow, shiny vehicle hoods or roadways, and is generally polarized in a plane parallel to the reflecting surface.
A major advantage of eye glasses having polarized lenses is the ability to reduce glare from light striking reflective surfaces. When such polarized glare is viewed through a polarizer, the glare is completely eliminated. Polarized sun glasses reduce glare by having a vertical transmission axis, but blocking the dominantly horizontally polarized reflected light from horizontal surfaces.
It is well known to make sun glasses having polarized lenses. U.S. Pat. No. 4,838,673, issued to Richards et al. on Jun. 13, 1989, describes a sunglass lens which includes two layers of ground and polished mineral glass laminated together with a polarized film between the two glass layers to form a single lens having an inner and an outer surface. An anti-reflectent coating is attached to the inner surface of the lens and a bigradient coating is attached to the outer surface of the lens. U.S. Pat. No. 5,327,180, issued to Hester, III et al., on Jul. 5, 1994, as another example of sunglasses having polarized lenses, describes a polarized lens and a pair of glasses incorporating the lens. Similar to the lens described by Richards et al., the lens described by Hester, III et al. includes two lens elements, preferably formed of mineral glass, laminated together with a polarization film therebetween. The laminated lens is also applied with anti-reflectent coating and additionally with waterproof coatings.
It is also known that a light polarizing visor can be incorporated into a glare shielding board to be pivotally secured adjacent to the rearview mirror of a vehicle, as described in U.S. Pat. No. 6,089,643, issued to Wang et al. on Jul. 18, 2000.
The reduction in glare by polarized lenses can be dramatic. Nevertheless, this is not fully recognized and appreciated by many members of the public who purchase sunglasses and who often are more concerned with the tint and general reduction of light provided by sunglasses rather than selective reduction of polarized light. Moreover, the importance of wearing swimming goggles or diving masks with polarized lenses has not been fully recognized even through it is well known that the polarized lenses are particularly effective around water. Polarized glare reflected from the water surface inhibits the water sport participant who is positioned on the ground for jumping or diving, from viewing under the surface of the water. This can be dangerous to the participant.
Generally, sunglasses cannot replace swimming goggles or diving masks because sunglasses cannot provide the eye protection offered by swimming goggles or diving masks, with the exception of light shielding. Polarized lenses available in the marketplace are thinner than normal lenses used for swimming goggles and diving masks, and cannot sustain water pressure and water impact forces related to water sports, especially when the wearer is jumping or diving into the water.
Another problem regarding polarized lenses used for water sport eyewear is delamination caused by moisture contacting the peripheral edge of the laminated polarized lens. The laminated polarized lenses are vulnerable to moisture encroaching from the peripheral edge thereof. Hester III et al. provide additional waterproof coatings to the laminated lens of sunglasses. However, the waterproof coatings do not protect the peripheral edge of the laminated polarized lens from contacting moisture. In prior art, lenses are affixed in frames of swimming goggles or diving masks, usually in a relatively water-tight manner to prevent significant water leakage into the goggles or masks when the goggles or masks are worn on the head of a wearer and a gasket around the frame is pressed against the wearer""s face. Nevertheless, this type of water-tight manner does not ensure that moisture is prevented from contacting the peripheral edge of the lens, encroaching from either side of the lens. It is common for a wearer to remove the swimming goggles or diving mask from his/her head and put same into water to wash off moisture condensation collected on the inner side of the lens. It is also noted that in prior art, lenses are received directly in frames, the sealing properties of which normally rely on the elastic deformation of the frames. As a result, the sealing properties provided by the frame around lenses are not adequate with respect to the requirement of preventing moisture from contacting the peripheral edge of the lenses, because the frame material must be rigid or semi-rigid in order to maintain its shape, which compromises its elastic properties and therefore adversely affects the sealing result.
The Applicant is aware of no swimming goggles or diving masks with polarized lenses currently available in the marketplace, nor is the Applicant aware of public documentation providing technical description of swimming goggles or diving masks with polarized lenses. U.S. Pat. No. 5,191,363, issued to Smith et al. on Mar. 2, 1993, describes sports glasses with a water-tight seal and merely mentions a lens, preferably polarized. Smith et al. neither address the particular sealing requirement of the peripheral edge of the polarized lenses, nor provide technical teachings for such a seal. Therefore, there is a need for swimming goggles and diving masks with polarized lenses which overcome the above mentioned problems.
It is one object of the present invention to provide swimming goggles or diving mask with polarized lenses.
In accordance with one aspect of the present invention eyewear is provided for water sports. The eyewear comprises at least one laminated polarized lens having means surrounding and sealing a peripheral edge thereof, for preventing moisture from contacting the peripheral edge of the laminated polarized lens. The lens and means forms a sealed lens unit. A frame is provided to receive the sealed lens unit affixed therein. Retaining means are attached to the frame for holding the eyewear against the face of a wearer thereof.
The eyewear used for water sports according to the present invention, in particular swimming goggles or a diving mask, preferably has the laminated polarized lens protected from water impact by a non-polarized lens.
The means surrounding and sealing the peripheral edge of the laminated polarized lens preferably comprise an elastomeric and water-impermeable ring in tension, covering and extending beyond the peripheral edge thereof; or preferably comprise a water-impermeable sealing film covering and extending beyond the peripheral edge of the laminated polarized lens in a water-tight manner.
In one embodiment of the present invention, the non-polarized lens is a conventional lens of swimming goggles or a diving mask. The sealed lens unit containing the laminated polarized lens with the seal ring as a single piece, for example, is glued to the inside of the swimming goggles or diving mask. Thus, the conventional lens that is positioned on the outer side of the sealed lens unit protects the polarized lens from water impact and the seal members, such as the elastomeric ring of the sealed lens unit protect the peripheral edge of the laminated polarized lens from contacting moisture even when the swimming goggles or diving mask are off the wearer""s head and are immersed in water.
In another embodiment of the present invention, the laminated polarized lens is laminated together with the non-polarized lens. A seal member, preferably the elastomeric ring, covers and extends beyond the peripheral edge formed by both the laminated polarized lens and the non-polarized lens in a water-tight manner, in order to prevent moisture from contacting the peripheral edge. The seal member secures the laminated polarized lens and the non-polarized lens together to form the sealed lens unit. The sealed lens unit containing the polarized lens is affixed in the frame of the swimming goggles or diving mask. The laminated polarized lens which constitutes layers of the sealed lens unit positioned in the swimming goggles or diving mask to be closest to the wearer""s face while in use, is protected by the non-polarized lens which constitutes the outer lens surface when positioned in the swimming goggles or diving mask while in use. The non-polarized lens is preferably made of polycarbonate plastic.
The glare eliminating feature of the swimming goggles or diving mask having polarized lenses according to the present invention is particularly useful for water sports where glare significantly inhibits participant vision. The swimming goggles or diving mask of the present invention provide the wearer with better vision through the water surface before the wearer jumps or dives into the water, to improve the safety of the water sport participant.
Other advantages and features of the present invention will be better understood with reference to preferred embodiments of the present invention described hereinafter.